The invention relates to a method for the manufacture of electrically conductive lead-throughs in metallized plastic housings for electronic applications.
Metallized plastic housings can be considered as an economical alternative to conventional metal housings for use in electronic and microelectronic applications. With the present state of the art, the manufacture of electrically conductive lead-throughs in metallized plastic housings is accomplished by various methods. One possibility is to press in simple metal pins or nailhead pins, or to insert the pins at the time of injection molding. A second possibility is to insert and solder or stick the pins in plastic housings already metallized. In both cases, however, it is necessary to insulate the pins with respect to the housing metallization in order to avoid electrical short-circuits. This is done by elaborate work operations such as masking at the time of applying metallization or by subsequent separation of the metallization layer around the lead-through holes or by sequential drilling or milling. In the case of pins that have been pressed in or integrally molded, there are problems in achieving the high degree of gas-tightness required for many applications. Another method provides for the soldering or sticking of relatively expensive glass-insulated metal pins in a manner similar to that for metal housings. Better gas-tightness is achieved in this way.
The object of the present invention is to specify a method for the manufacture of electrically conductive lead-throughs in metallized plastic housings in which the insulation of lead-through pins with respect to the housing metallization can be realized simply and at low cost. At the same time, gas-tightness and electromagnetic shielding is to be achieved.